Repentance is an essential mark or characteristic of a Christian. Not only must we repent to be saved (Mk. 1:15; Acts 11:18; 20:21), but the Christian life is characterized by repentance. This characterization is seen in two ways: first, by producing good works that are keeping with, or that evidence, true repentance (Acts 26:20), and second, by confessing and repenting of sin when we do sin (Heb. 12:1-2; 1 Jn. 1:9).
What exactly is repentance? How is it defined? Repentance is a change of mind, wrought by God’s grace, that causes us to view sin differently – from loving it to hating it. This change of mind is accompanied with a turning toward God and trusting (faith) in His promises. “For they themselves report about us what kind of a reception we had with you, and how you turned to God from idols to serve a living and true God, and to wait for His Son from heaven, whom He raised from the dead, that is Jesus, who rescues us from the wrath to come” (1 Thess. 1:9-10). The Shorter Catechism provides an excellent definition for us:
Q. 87. What is repentance unto life?
A. Repentance unto life is a saving grace, whereby a sinner, out of a true sense of his sin, and apprehension of the mercy of God in Christ, doth, with grief and hatred of his sin, turn from it unto God, with full purpose of, and endeavor after, new obedience.
Repentance, then, is evidenced by conviction of sin and its consequences, as that which brings displeasure to God, and a whole-hearted desire to live unto God in a manner pleasing to Him, because of the grace and mercy He has shown to us in and through Christ. True repentance is that which flows from godly sorrow, leading to life, but sorrow of the world leads only to death (2 Cor. 7:9-10).